I'd agree that the best trainer should be better at their job than a computer. Unfortunately, 9/10 PT's get their certs off the back of a cereal box, so 9/10 of them do an even worse job than a mindless computer program.
Remember, of course, that 2 big components of personal training are one-on-one face time, and coaching. A computer program putting together an exercise program is easy. Exercise programming IS easy, and as much as we all typically say that everyone's different, the truth is 90% of people will improve their overall health, function and body composition by making the exact same adjustments: learning the big compound movements (squat, bench, press, deadlift, chins, rows), doing some general conditioning/general physical preparedness, and eating better (more fruit and vegetables, less foods where the wrapping is more colourful than the contents). That's the easy part of the job. That's the part you can get FOR FREE, and rightly so - no one should have to pay to have access to basic, fundamental information on how to not be a lazy ****** dying of lifestyle diabetes.
However, the face time with a PT is worth something. It's here where things get fleshed out, where you get motivation and enouragement, and where you're likely to start enjoying exercise (or learn to hate exercise even more because the PT's an assbutt). Perhaps even more valuable, at least from a results point of view, is coaching. Computers don't make for very good coaches. Humans are more likely to be decent coaches. Is a computer program going to know that you're not squatting deep enough, or that your butt tucks under when you squat, or that one hip drops faster than the other, etc? Probably not. A competent trainer will probably pick up on these things, and work on them with you.
There are a lot of good exercise programs out there that you can get for free. There's often books associated with these programs, that might cost some money, but the programs themselves are often free.
I think having a human PT online, who gives and tweaks your programs according to your goals and any roadblocks you may encounter along the way, who you can email back and forth, who checks your training videos to constructively critique your form, and who ultimately teaches you to train yourself, is worth something. Depending on how much interraction you have with them, something like $20/week for that service could be a very worthwhile investment.
And of course, a competent PT in person is worth big bucks. $60-100/hr is about the industry standard here, and as I said before, 9/10 PT's are underskilled, so a competent PT is probably worth $100+ (of course they probably won't charge that much - few competent PT's are sales-oriented enough to believe that they can charge that much, but if the average PT is worth $60-100, then competent PT's are worth more than that.